16.Icon、ImageIcon标签

Icon标签：

package com.gui.lesson4;

import javax.swing.*;
import java.awt.*;

//图标，需要实现类，Frame继承
public class IconDemo extends JFrame implements Icon {

    private int width;
    private int height;

    public IconDemo() {//无参构造
    }

    public IconDemo(int width, int height) {
        this.width = width;
        this.height = height;
    }

    public void init() {
        IconDemo iconDemo = new IconDemo(15, 15);
        //图标放在标签，也可以放在按钮上！
        JLabel label = new JLabel("icontest", iconDemo, SwingConstants.CENTER);

        Container container = getContentPane();
        container.add(label);

        this.setVisible(true);
        this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

    }

    public static void main(String[] args) {
        new IconDemo().init();
    }

    @Override
    public void paintIcon(Component c, Graphics g, int x, int y) {
        g.fillOval(x, y, width, height);
    }

    @Override
    public int getIconWidth() {
        return this.width;
    }

    @Override
    public int getIconHeight() {
        return this.height;
    }
}

ImageIcon标签：

package com.gui.lesson4;

import javax.swing.*;
import java.awt.*;
import java.net.URL;

public class ImageIconDemo extends JFrame {
    public ImageIconDemo() {
        //获取图片的地址
        JLabel label = new JLabel("ImageIcon");
        URL url = ImageIconDemo.class.getResource("tx.jpg");
        ImageIcon imageIcon = new ImageIcon(url);
        label.setIcon(imageIcon);
        label.setHorizontalAlignment(SwingConstants.CENTER);

        Container contentPane = getContentPane();
        contentPane.add(label);

        setBounds(100, 100, 300, 300);
        setVisible(true);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }

    public static void main(String[] args) {
        new ImageIconDemo();
    }
}